Blessed and blessed are participles from the verb bless. The first is regular, and the second comes from the Latin participle benedictus. Blessed is the only form that should be used in the formation of compound time and passive perifrastica ( «»The Bishop has blessed the young couple loves», «the work was blessed by the Bishop» ) while the blessed way only is used as adjective and noun ( «»A bit of holy water can do him wrong», «You slumbered as a blessed in bed» 41.
